1. Field of the Invention
The present invention relates to image forming apparatuses including electrophotographic printers and copying machines.
2. Description of the Related Art
A conventional electrophotographic image forming apparatus performs processes of charging, exposing, developing, transferring, and fixing in sequence to print an image on a print medium. A charging unit charges the surface of a photoconductive drum uniformly. An exposing head illuminates the charged surface of the photoconductive drum in accordance with print data to form an electrostatic latent image. A developing unit supplies toner to the electrostatic latent image to develop the electrostatic latent image into a toner image. A transfer unit transfers the toner image onto the print medium. The print medium advances into a fixing unit where the toner image is fused into a permanent image. Some conventional electrophotographic image forming apparatuses include an indicator that indicates a remaining amount of toner in the toner reservoir. The indicator indicates to a user that the toner reservoir is reaching its empty state, thereby prompting the user to replenish the tone.
Printing may still be performed even when the toner is nearing exhaustion. Therefore, it is common that the user continues to print. However, continuing to print with the remaining toner nearing exhaustion may cause vague images, resulting in poor image quality.